textproduct: Albany

WHAT HAS CHANGED

No significant changes were made during this update as the previous forecast remains on track.

KEY MESSAGES

1)Temperatures return to near normal levels for the end of the work week before the brief introduction of an anomalously cool airmass leads to below normal conditions on Saturday.

2)A period of light rain is expected across portions of eastern New York and western New England Friday afternoon through Saturday morning. Despite uncertainty in the exact precipitation amounts, low to medium chances (~10-70%) for at least 0.25" gives high confidence in a lack of resulting flooding.

DISCUSSION

KEY MESSAGE 1...

In the wake of yesterday's cold front, we remain under broad troughing aloft with with a northwest flow regime advecting cooler air into the region. As such, temperatures are anticipated to lower to more seasonably normal levels today with highs spanning the upper 50s to low 70s. By late tonight, a shortwave embedded within the mean trough aloft will have departed to our south and east, allowing flow to begin backing to the west. This new flow regime, paired with deep mixing; localized downsloping into valley areas; and a slight increase in geopotential heights aloft will subsequently allow highs to tomorrow to rise a few degrees warmer than today.

By tomorrow afternoon, a potent upper low and associated surface cyclone will be sinking towards the region from Quebec. The passage of this system Friday afternoon through Saturday morning will result in the brief advection of an anomalously cool airmass (1.5 to 2 STDEVs below normal) and subsequent below-normal surface temperatures. Highs Saturday will therefore span the 50s to low/mid 60s with lows Saturday night falling to the upper 30s to mid 40s. But the swift departure of this system and the building in of a high from the west will bring temperatures back to normal levels for Sunday into the beginning of the new work week.

KEY MESSAGE 2...

As mentioned above, a potent system will track through the region tomorrow afternoon through Saturday morning. This looks to be out next best chance for more widespread showers. However, differences shown in both deterministic and ensemble guidance in the track of this system continue to drive uncertainty in the spatial spread of showers and the resulting rainfall amounts. As of this update, most ensemble solutions maintain the track of the upper-level cyclone largely to our east thereby also keeping the core of the surface low and the better forcing to our east. We erred on the side of this solution with this forecast as this is similar to the trends that have been seen over the last couple of days. This would ultimately limit the rainfall seen to the west of the Hudson River Valley to less than 0.1". Areas to the east, and the Southern Adirondacks where persistent, moist cyclonic flow and orographic enhancement could lead to greater QPF, would therefore see the greatest rainfall amounts of about 0.1" to 0.2". Given our drier conditions over the last couple of days, as well as the longer duration of the rainfall, these amounts would be beneficial and pose no flooding concerns. That said, even the outlying solution wherein the the track of the system is farther west, keeps rainfall amounts to around or under 0.25" to 0.5". Therefore, we have high confidence that this event will not create any flooding.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Through 12z Friday...VFR conditions are expected to prevail through the 24 hour TAF period for all terminals. Mid-to-high clouds will gradually lower throughout the morning and afternoon as another disturbance moves across the region. Isolated showers are possible this morning and afternoon at KGFL, KALB, and KPOU, reflected by PROB30 groups, but no significant impacts to cigs or vis are expected if these do occur. Cigs are expected to bottom out around 3-5 kft, with KPSF potentially dropping down to MVFR overnight into Friday. Cigs are expected to scatter out and rise thereafter through the end of the TAF period.

North-northwesterly winds will prevail for the entire TAF period. Winds will start off moderate during this TAF period with gusts expected to reach up to 15-25 kts through this evening. Winds/gusts will begin to subside around 00Z Friday, down to around 3-5 kts through the end of the TAF period.

Outlook...

Thursday Night: No Operational Impact. NO SIG WX. Friday: Low Operational Impact. Breezy. NO SIG WX. Friday Night: Moderate Operational Impact. Breezy. Chance of SHRA. Saturday: Low Operational Impact. Breezy. Slight Chance of SHRA. Saturday Night: No Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Slight Chance of SHRA...TSRA. Sunday Night: Low Operational Impact. Slight Chance of SHRA. Monday: Moderate Operational Impact. Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.